1. Field of the Invention
The present invention relates to methods and apparatus for supporting modular furniture of the type used in offices. The method involves the use of lifting means to allow access to an office floor, e.g. for replacement of carpets or other flooring, including panels of raised flooring, without the need to remove the furniture from the office.
2. Prior Art
Modern offices are often provided with so-called "modular furniture", which comprises an arrangement of panels interconnected at angles to form office dividers, and which have so-called "hanging tracks" used to support desks, bookshelves, and other necessary office equipment. These hanging tracks are vertical metal strips, usually located near the edges of the panels, having a series of undercut slots from which special hangers, with suitable hooks, can be suspended. Generally, these hanging tracks are aligned with feet which support the panels, and which usually provide the only contact between the floor and the modular furniture.
The fact that quite a number of such panels, and their associated desks and shelves, are connected together makes it time consuming and costly to dismantle this furniture and remove it from an office to allow carpeting or other flooring to be replaced. Accordingly, apparatus has been designed and used which will allow the panels and associated furniture to be temporarily raised so that new flooring can be placed underneath. Apparatus of this kind is described, for example, in:
U.S. Pat. No. 5,261,643, issued Nov. 16, 1993 to Wurdack;
U.S. Pat. No. 5,299,779, issued Apr. 5, 1994 to Collins;
U.S. Pat. No. 5,385,335, issued Jan. 31, 1995 to Wurdack;
U.S. Pat. No. 5,490,757, issued Feb. 13, 1996 to Stratman;
U.S. Pat. No. 5,529,287, issued Jun. 25, 1996 to Pelosi, Jr. et al.; and
U.S. Pat. No. 5,628,610, issued May 13, 1997 to Stratman et al.
Several of these patents use lifting jigs which have plates with a series of hooks for engaging the hanging tracks of the panels; for example the Wurdack patents, and those of Stratman and Pelosi et al. have this feature. Another lifting device, and one which has more stability than the prior devices, is described in Applicant's co-pending Canadian Patent Application No. 2,223,736, filed Feb. 18,1998. This lifts the panels by engaging their undersides, near to the legs, and thus avoids applying upwards force to the hanging tracks, since in some makes of panel such forces may cause the hanging tracks to be dislocated.
Another shortcoming of the previously patented arrangements is that it is difficult or impossible to place carpeting underneath the leg of a panel, since this is usually where the lifting device is positioned. Some installers simply accommodate the panel leg and/or the lifting device by cutting out a portion of the carpet or carpet tile, or slitting this around the leg. In our co-pending Canadian patent application aforesaid, a bridge member is provided having feet which can be placed at either side of a leg, and the bridge member carries a saddle member with auxiliary jacking means which can be used to lift the leg portion of a panel while leaving a clear space under the leg area where reflooring can be done. This bridge is good for spanning a space 3 feet or possibly 4 feet wide, and is suitable particularly where the flooring is supplied in the form of carpet tiles.
However, if it is desired to install strips of carpeting supplied in rolls, there is often a need for providing a clear space under aligned panels of more than 4 feet width, and sometimes more than 6 feet width, which requires a larger bridge than in the system described in our copending Canadian application. Another limitation of this system is that in many cases the low or "floor level" bridge described in our Canadian copending application would meet interference from other panels connected at right angles to the panels being lifted by the bridge system. The present invention provides a system which includes both a provision for a greater width of clear space, suitable in the preferred form for installation of a 6 foot wide carpet strip, and also provides a system in which bridge members used to support the lifting means can be high enough not to interfere with connected panels.